九變

• Rules matter, but rigid obedience fails when conditions change.
• Alternate chapter title: Variation of Tactics
• Chinese chapter title: 九變
• This chapter is grouped into three contextual rule cards while preserving the full traditional Chinese text.

• Core idea: Some roads should not be taken, some forces not attacked, some cities not assaulted, some ground not contested, and some commands not obeyed.
• Meaning: Strategy includes disciplined refusal.
• Why it matters: Context can overrule default doctrine.
• How to apply: Ignore a top-down request if execution would clearly destroy the larger objective, but document the reasoning.

Original Text Explanation

孫子曰：凡用兵之法，將受命于君，合軍聚眾，

Sun Zi says that in war the general receives the ruler's command, gathers the army, and concentrates the host.

圮地無舍，衢地交和，絕地勿留，圍地則謀，死地則戰。

Do not encamp on difficult ground. On intersecting ground, join with allies. Do not linger on isolated ground. When hemmed in, use stratagem. On desperate ground, fight.

途有所不由，軍有所不擊，城有所不攻，地有所不爭，君命有所不受。

There are roads not to follow, armies not to attack, cities not to assault, ground not to contest, and commands from the ruler not to accept.

故將通于九變之利者，知用兵矣﹔

The general who understands the advantages in such variations knows how to employ troops.

將不通于九變之利，雖知地形，不能得地之利矣﹔

The one who does not understand these variations may know terrain and still fail to turn it into advantage.

治兵不知九變之朮，雖知地利，不能得人之用矣。

And the commander who does not understand this flexible method may know the ground's benefits and still fail to get the best use from his men.

• Core idea: The wise mix benefit and danger in every calculation.
• Meaning: Evaluate upside and downside together.
• Why it matters: One-sided thinking produces fragile plans.
• How to apply: Every major launch review should include both growth opportunity and failure mode.

Original Text Explanation

是故智者之慮，必雜于利害。

So in a wise person's calculations, advantage and harm are always considered together.

雜于利，而務可信也﹔

When advantage is weighed alongside risk, the main design can be carried through with confidence.

雜于害，而患可解也。

When harm is weighed alongside possible gain, danger can be escaped.

是故屈諸侯者以害，役諸侯者以業，趨諸侯者以利。

That is why rival rulers can be constrained through harm, occupied through burdens, and drawn where you want them by advantage.

• Core idea: Do not rely on the enemy not coming; rely on your own readiness. Do not rely on the enemy not attacking; rely on your own strength.
• Meaning: Hope is not a defense plan.
• Why it matters: Preparedness must come from your side, not from guessing their restraint.
• How to apply: Build real incident response capacity instead of assuming outages or attacks are unlikely.

Original Text Explanation

故用兵之法，無恃其不來，恃吾有以待也﹔無恃其不攻，恃吾有所不可攻也。

The rule of war is not to rely on the enemy's failure to come, but on your readiness to receive him; not on his refusal to attack, but on your own unassailable position.

故將有五危：必死，可殺也﹔必生，可虜也﹔忿速，可侮也﹔廉潔，可辱也﹔愛民，可煩也。

A general has five dangerous faults: recklessness that gets him killed, fearfulness that gets him captured, a hot temper that can be provoked, touchy honor that can be insulted, and excessive concern for the troops that turns into trouble.

凡此五者，將之過也，用兵之災也。

These five are the general's failings and disasters in war.

覆軍殺將，必以五危，不可不察也。

When an army is destroyed and its commander slain, the cause will almost always be found in one of these five. They must be studied carefully.